1. Field of the Invention
The present invention relates to sample analyzers for analyzing samples using reagents.
2. Description of the Related Art
Conventionally, a number of sample analyzers have been developed that analyze samples such as blood, blood serum, blood plasma, urine, or spinal fluid using reagents. In such sample analyzers, when reagent containers containing reagents to be used for sample measurement become empty, samples cannot be measured during replacement of the empty reagent containers.
WO2007/047069 discloses a system in which even when a reagent container containing a reagent becomes empty, the reagent can be processed continuously. The system disclosed in WO2007/047069 includes a feeder chamber and a buffer chamber between the reagent container and a reagent consuming station. Therefore, even if the reagent container becomes empty, the reagent remaining in the feeder chamber and the buffer chamber can be processed continuously.
Furthermore, U.S. Pat. No. 5,428,993 also discloses an automatic analyzer in which even when a reagent container containing a reagent becomes empty, sample measurement can be continued. In the automatic analyzer disclosed in U.S. Pat. No. 5,428,993, a main reagent container and a sub reagent container are connected to each other through a valve. When the main reagent container becomes empty, the valve is switched to the sub reagent container side. This allows sample measurement to be continued using the reagent contained in the sub reagent container.
Moreover, the automatic analyzer of U.S. Pat. No. 5,428,993 outputs a warning when the total amount of the reagent remaining in the main reagent container and the reagent remaining in the sub reagent container becomes less than a predetermined amount. Furthermore, the automatic analyzer outputs a warning message indicating a shortage of the reagent when one of the reagent containers becomes empty.
WO2007/047069 neither discloses nor suggests any operation that the system disclosed therein carries out when the reagent container becomes empty. The user of the system, therefore, was not able to determine the timing of replacement of the reagent container. On the other hand, the automatic analyzer disclosed in U.S. Pat. No. 5,428,993 outputs the warning message indicating the shortage of the reagent when one of the reagent containers becomes empty. Thus, the user of the automatic analyzer can recognize the shortage of the reagent.
However, the automatic analyzer disclosed in U.S. Pat. No. 5,428,993 is based on the premise that a plurality of reagent containers containing the same type of reagent are connected. Therefore, the automatic analyzer is different in the premise from the system of WO2007/047069 that is not based on the premise that a plurality of reagent containers containing the same type of reagent are connected.